401(k) Loan: How Borrowing From Your Retirement Works

A 401(k) loan lets you borrow money from your own retirement account and pay it back over time, usually with interest, without triggering the taxes and penalties that normally come with an early withdrawal. It sounds simple, and in some ways it is. But the details matter, because you are borrowing from money that was supposed to grow for decades.

This guide walks through how a 401(k) loan works, what the rules are, and what can go wrong. It is educational information only, not advice. Investing carries real risk, including the chance of losing money, and borrowing from a retirement account adds its own set of tradeoffs.

What a 401(k) Loan Actually Is

A 401(k) loan is money you take out of your workplace retirement plan and agree to repay. You are both the lender and the borrower. There is no bank on the other side of the deal, no credit check, and no entry on your credit report.

That last part surprises people. Because there is no third-party lender, a 401(k) loan does not show up on your credit reports and does not affect your credit score. It also does not count as debt in the way a personal loan does. For a beginner trying to understand the difference between a 401(k) and an IRA, the key point is that IRAs do not allow these loans at all. Only workplace plans like a 401(k) or 403(b) can offer them, and even then, the plan has to choose to include the feature.

Not every 401(k) plan allows loans. Some do, some do not, and the ones that do can set their own rules on top of the federal limits. Your plan document is the source of truth.

How the Borrowing Limits Work

Federal rules cap what you can borrow. In general, the maximum is the lesser of 50% of your vested balance or $50,000. Vested means the portion of the account you actually own. Your own contributions are always 100% vested. Employer matching contributions may vest over a schedule, so a chunk of your balance might not be eligible to borrow against yet.

There is one wrinkle worth knowing. If your vested balance is under $10,000, you may be able to borrow the entire amount rather than just half. And if you already have an outstanding loan, the rules can reduce how much new money you can take.

Here is a quick look at how the cap plays out at different balances:

Notice the last row. Once your balance is large enough, the $50,000 ceiling takes over and the 50% rule stops mattering.

The Moving Parts: Interest, Repayment, and Taxes

Three things drive how a 401(k) loan behaves: the interest rate, the repayment schedule, and the tax treatment.

Interest rate. The Department of Labor requires plan loans to charge a reasonable rate. There is no single required number, but plans often tie the rate to the prime rate. The interest you pay does not go to a bank. It goes back into your own account, which is why some people describe a 401(k) loan as paying interest to yourself.

Repayment. Most loans must be repaid within five years, in level payments made at least quarterly. If the loan is used to buy a primary home, the plan may allow a longer term. Payments are often pulled straight from your paycheck, which makes them easy to forget about until you change jobs.

Taxes. A properly structured 401(k) loan is not a taxable distribution. You avoid the 10% early withdrawal penalty that normally applies before age 59½. But there is a catch on the back end. You repay the loan with after-tax dollars. If the money goes back into a traditional 401(k), you will pay income tax again when you withdraw it in retirement. That is a real cost, even though no one sends you a bill for it today.

If you leave your job with a loan balance outstanding, many plans require you to repay the full amount quickly, sometimes within 60 to 90 days. Miss that window and the unpaid balance can be treated as a distribution, which means income tax and possibly the 10% penalty. If you are weighing a job change, it helps to understand how to track down an old 401(k) and what happens to loans when you move on.

A Worked Example: Renata Borrows $20,000

Renata is 41 and works as a hospital lab manager. Her 401(k) has a vested balance of $96,000, and her plan allows loans at a fixed 5% rate with monthly payroll deductions. She wants to borrow $20,000 to cover a roof replacement.

First, check the cap. Fifty percent of $96,000 is $48,000. The federal ceiling is $50,000. The lesser of those two is $48,000, so a $20,000 loan fits comfortably.

Next, the term. She chooses the standard five-year repayment, which is 60 monthly payments. At a 5% annual rate, the monthly payment on a $20,000 loan works out to about $377. Over 60 months, that is roughly $22,640 in total payments, meaning about $2,640 in interest flows back into her account.

Now the part people miss. While the $20,000 is out of the market, it is not growing. Suppose the account would have earned 6% a year. On $20,000, that is $1,200 in the first year alone. Because the money is on loan, that growth does not happen. Renata does pay herself back with interest, but the interest is calculated on the declining loan balance, not on what the full $20,000 could have earned.

The math is not automatically bad or good. It depends on how the market performs and how quickly she repays. If markets fall while she is out, she may actually come out ahead. If markets rise, she may fall behind. No one can predict which happens.

What Changes If the Numbers Shift

Two inputs move the picture the most: the interest rate and the loan term.

Suppose Renata's plan charges 7% instead of 5%. Her monthly payment rises to about $396, and total interest paid climbs to roughly $3,760. The extra $1,120 stays in her account, so a higher rate is not purely bad for her retirement balance. But it does raise her monthly cash outflow.

Now suppose she stretches repayment to 10 years because the loan is for a home purchase. At 5% over 120 months, the payment drops to about $212 per month. That is easier on her budget, but the money stays out of the market twice as long, and total interest paid rises to roughly $5,440. A longer term lowers the monthly burden and raises the long-run opportunity cost at the same time.

Compare that to the current average credit card APR of 20.94% as of May 2026, per the Federal Reserve. A 401(k) loan rate is usually far lower. That gap is why some people consider a 401(k) loan when the alternative is high-interest debt. Whether that tradeoff makes sense depends on the person and the situation.

Common Mistakes People Make With 401(k) Loans

Mistake 1: Assuming the plan allows loans. Many plans do not. Before building a plan around a 401(k) loan, confirm the feature exists. If it does not, the conversation is over.

Mistake 2: Forgetting the job-change risk. People take a loan, then change jobs a year later, and suddenly the balance is due in 60 days. That is when a manageable loan turns into a tax problem. If a job change is on the horizon, this risk deserves real weight.

Mistake 3: Treating the interest rate as the whole cost. The bigger cost is often the growth the money would have earned while invested. A 5% loan rate looks cheap next to a credit card, but the missed compounding on the borrowed amount can dwarf the interest difference over time.

Mistake 4: Stopping contributions while repaying. Some plans let you keep contributing while you repay; others suspend contributions. If contributions stop, you may also miss out on the employer match. That is free money walking out the door. To see how much a match matters, look at how employer matching works.

For a broader view of how workplace plans compare to older pension-style plans, the guide on pensions versus 401(k)s is a useful companion read.

Where This Leaves You

A 401(k) loan is a real feature of many workplace plans, and it can be a lower-cost way to access cash than some alternatives. It is also a decision with long tails, because the money you borrow is money that is not growing for retirement. The rules are set by your plan and by federal limits, and the tax treatment depends on whether you repay on time and whether you stay at your job. Understanding those mechanics is the first step before deciding anything.

Editorial note: Interest rates and economic data can change frequently. Figures in this article are based on the latest publicly available data at the time of publication and should be checked against the cited primary sources for the most current values.